Ordered my Magic pie KIT 17-11-2009 Netherlands

[Hardcore]

Best regards Jeroen Compagne

www.beeldhout.nl

nice bike you got there,

kevin h.

[Bikemad]

Fitted my stand alone cycle analyst. I have read about some great xtra options and would like to use the speed limmiting function of the cycle analyst. I think however the voltage to the controller will go down when you use the speed limmiting function of the cycle analyst..........   Will this cause the controller to get into safety low voltage cut out mode?  

Jeroen,

There's no need to worry about low battery voltage going to the controller as this does not happen with the Cycle Analyst.
The Cycle Analyst achieves the speed and current limiting by overriding and reducing the throttle signal voltage going to the controller, not the battery voltage.

Your build is looking very nice so far, and it's good to see the pictures of your progress.
I bet you're really looking forward to getting the battery fitted now!

Next thing I did was fit the wheel. WOW its very much of centre. Did read about this in the forum already but did not think it would be this much. I don't think I will be able to fit a normal atb tire. Will have to look for something a lot narrower. I also read about someone respoking the wheel to counter the of center problem. How did this work. (any pictures?)

The rim is not exact in the middle but it works fine.
I am thinking of realign the wheel. Shorten the spokes in the Sprocket side and make the spokes on the diskbrake side longer.
The rim will go to the middle of the bike. Like with a racingbike wheel Fig. A.

Thanks for the reply.
Because the Magic Pie has such a narrow gap between the spoke flanges, I don't think you will be a ble to offset the rim very much, I guess about 4-5mm might be just possible without reducing the wheels lateral rigidity too much.

It would be nice to have an update on how successful you are with trying to realign the rim.

Alan
 

I reallign the wheel with the spokes. The rim is moved 5 mm to the sprocketside. That is not much but the tyre was very close to the frame. Now there is a bit more space.

Good luck with the rest of the build.

Alan
 

[Jazzjerry]

28 dec 2009

Ok next update.

I discovered some problems caused by myself. I have a 28" wheel bike but it has a ISO Bead Seat Diameter of 622.
The Magic Pie wheel I ordered is also 28" but has a ISO Bead Seat Diameter of 635.

Pffff Wel here is the problem. I cant find any suitable tyres low profile enough to fit the pie's rim and not hit the frame since it is off center so much already, and now also is larger then the origional rim.

So I have planned to get a new rim spoked around the pie. Next problem that arises where can you find somebody to do that for you? Well I found a place here nearby. I hope they wil be capable to help me. The spokes are thicker and I think are size 13. Normal pushbikes have spokes size 14 which are thinner. Pushbike rimms have holes that fit spokenipples 14. The spokenipples for a spoke 13 are to wide and wont fit a standard pushbike rim.

Solution.......

There are Spokenipples for a rim with spokenipple holes 14 but have the wider threading for spokes 13. Problem is the spokenipples are very thin walled and get damaged easely.

I think I am going for the second solution. Just fit the thinner size 14 spokes .
When I look at the origional spokes of the pie the threading is that of a spoke 14 and the thicknes of the spokes are spoke 13. This means that the spokes are in effect spoke 14 since they will snap of at the thinnest part which is the thread anyway.

So why not choose normal spoke 14 size spokes anyway. I amthinking of RVS black spokes.

Keep you guys updated.

Jeroen Compagne

www.beeldhout.nl

P.s.

Thanks for the replies Hardcore and Bikemad.

Good to hear the cycle analyst should work without a problem. Will dig in configuring that when I get to that stage.

[Jazzjerry]

29 dec 2009

Took the pie to the bikeshop to get it respoked. Will be finished around the 4th Jan 2010 (next year) 

Also started on some soldering. The shunt resistor from the cycle analyst is a stand alone version and needs to be positioned between the battery and the controller. I liked the idear of having the cycle anayst pluggable so I can choose to ride without or even use 1 cycle analyst on more then 1 bike. So I soldered some high Amp connectors to the Shunt resistor so I can either ride with or without the cycle analyst.

To be able to do this I bought 4 connectors. Bat wire-Connector-Connector-Shunt resistor-connector-connector-power wire going to the controller.

So now I can loose the shunt and connect bat and controller without it by simply plugging in.

[Harvey_Mushman]

Wow, those connectors are bombin'!  Power Poles would have done well, but I admit to being a fan of over-kill. 

Wondering what the RShunt threshold for an MP might be..

..need that value for proper CA calibration..

[Jazzjerry]

 

7th Jan 2010

Lol yes they are a bit overkill but the only thing I was able to get in the sence of quick connectors that are safe in the sence that the polarity can only be plugged in 1 way. I know myself all to well and would make a mistake 1 day otherwise....... (murpy's law) and me make a wonderfull combination.....  

Also according to my calculations the pie will pull out 27.5 amps..... Which is a load to think about. I even find the orrigional wires in the hub a bit on the thin side for this power. The connectors are 50 Amps...

I also ordered a blackbox (plastic watertight electrical circuit box) that I am going to fit on my frame instead of the bottle holder.



 I am going to try an let all the ends meet in here. So all the connectors and wiring wil somehow end up in there. The rest of the wiring I am going to shrinkwrap in black tube and tywrap to the bike to make a clean install.

Meenwhile I am still waiting for my battery. Also I looked at the battery caryer rack and it is completely bent in al directions.

Look at this photo.

I dared and bent it back but it felt like some of the welds snapped of a bit. Dont dare and touch it any more because I am too scared it will break. Maube GM can send me a new one. I would love to test out the new rack. So if Yao Yuan reads this.... I am a willing tester for your new battery rack......  

And another picture of the proces so far.
Nearly all the wireing is in place from the steering wheel to the connector box I am planning to build.

[Gapy]

You tied your bike to a seat funny

[Jazzjerry]

12 Jan 2010

Where is my Battery?.......?......

Waiting for some lithium..... Will call Dennis soon to see if he knows more, Starting to get inpatiënt..

Regards,

Jeroen Compagne

www.beeldhout.nl

[Jazzjerry]

14 jan 2010

Received the bat.
Checked it and it had 50,9 volts showing on the cycle analyst.

[Koga]

Did the new wheel lacing compensate for the of centered pie? or did you only fit a new rim?

[Jazzjerry]

It is still at the bike repair shop getting laced. So I have no update on that yet.

Should be ready in 2 weeks. Takes them a long timeto get the rim I wanted.

Will show the new alignment here in the forum.

[Leslie]

This off center is very strange.... Check this, from the GM web site:

Any one knows why, or if this is correct? Do we correct this with washers and nuts?

Yes it is so you can have all the gears and a disc brake so Yuan says.

You have an alloy frame.  Make sure the bike shop knows not to spread the frame for the hub to be centred.

Before you pedal that 6 speed cluster tight Id change to a five speed or three and centre the hub.


The method of off true wheel has been reported to not fully centre the rim over the hub and IMO is inherently weaker than a properly chewed rim, because the angle of spoke to spoke flange is different on both sides both sides.  One has to question how much spoke thread will be remaining on the far side as well.

Like when you start a building card house the two first cards will lean upon each other in an A frame.  If they are not straight  one side will give out.  I envisage over time this imbalance will twist the rim. Even an off centre wheel will be much stronger than this and the off centre wheel is as strong as any normal hub and rim, as the balance is always achieved by the riders weight distribution, so too, equal tension is distributed on both left and right spokes..

[Jazzjerry]

I will mount the wheel myself,

Not letting any other work done on the bike then the respoking (is something I have never done before and looks to me like a lot of precision work) And I must say I am not looking foreward to doing that myself.

But I don't think a five gear unit would help center the wheel. The axle is what it is and I cant realy take out washers on one side and put extra,s on the other either.Or is there a way to shift the axle inside the hub?

[GM Brazil]

I agree with Jazzjerry,

I have not seen my wheel yet, but the same designs with a sprocket having a smaller number of gears, which sets the position is the longitudinal axis Geometry! "shoulders" of the shaft will still be in the same relative position! If this really is a chronic problem, GM will have to redesign the outer ring of the engine, keeping the engine in position, but shifting the fulcrum of the spokes.

Fulcrum... Is a correct use of the word?

Bruno

[Leslie]

I agree with Jazzjerry,

I have not seen my wheel yet, but the same designs with a sprocket having a smaller number of gears, which sets the position is the longitudinal axis Geometry! "shoulders" of the shaft will still be in the same relative position! If this really is a chronic problem, GM will have to redesign the outer ring of the engine, keeping the engine in position, but shifting the fulcrum of the spokes.

Fulcrum... Is a correct use of the word?

Bruno

I can only assume that the MP uses a spacer sleeve tube like my HBS36 that inserts within the sprocket as a support between the axle shoulder and the dropout .  A smaller cassette and 20 seconds on the grinder with the spacer sleeve should give you enough space on the sprocket side and then make up for it on the left side with washers to move the centre into centre.

Unless it's the sprocket side that's too close, Or the axle shoulder extend out to meet the dropout.

Edit:

Ohh I see.



The axel shoulder extends out of the cassette unlike the HBS sersies.

My bad.

If you really needed centre I would spread the frame or for an alloy frame, I would cutter grind the axle using the axle square (flat parts) as a guide then come down vertically with the grinder and remove pieces, then go for a smaller sprocket and washers.  Use a water flow to manage the heat.

When I go for a Pie soon (i hope) I'll make sure I use a frame that can tolerate a dropout spreading.